JPS6124178A - Method of contacting conductor with conductive strip or conductive layer in thermal resistant manner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application: The present invention relates to a method for bringing a conductor, such as a wire, a metal sheet, etc., into heat-resistant contact with a conductive strip or layer.

Prior Art: For this purpose, attempts have been made in the past to contact thick-film conductive strips with hard solder, but this only leads to a poor electrical and mechanical bond in practice. . In particular, the adhesive strength of known bonds of this type was unsatisfactory. This is because the metal coating on the ceramic substrate was dissolved during soldering in the solder metal, so that no firm adhesion to the substrate was any longer possible.

Effect: In a different way, the first layer is placed on the conductive strip or conductive layer 2
A conductive thick film paste 3 is applied to the conductive thick film paste 3, a conductor 4 is subsequently placed or buried in an undried state on or in the conductive thick film paste, and then heated to a temperature of about 500°C.
The method according to the invention, which is characterized in that baking is carried out with It has the advantage of achieving bonding. The bond obtained by the method of the invention is maintained even at high and very high temperatures. This is because the high temperature baked bond from the conductive thick film paste is not compromised by high temperatures and still maintains its reliable conductivity and mechanical adhesion.

The method of the invention has proven to be particularly effective for contacts of this type on ceramic substrates which are arranged, for example, in the exhaust gas of internal combustion engines. During the burning process of the thick-film paste, a tight bond between the conductor to be fixed, the paste and the conductive strip or layer is obtained. This method can be carried out in one furnace treatment, generally without vacuum and without protective gas, and is therefore particularly economical. Good bond strength and high loadability are guaranteed both over temperature and under current load. Preferred for use are, for example, temperature sensors, heating platelets, heating solobes and diesel engine preheating taps. Temperature sensors contacted according to the method of the invention provide a particularly high vibration resistance as well as a reliable electrical contact, which is essential for use in motor vehicles. For temperatures up to about 800°C, this temperature sensor has a temperature of about 0.1 to
A8-wire with a diameter of 0.5 mm, and also Pt-
Combined with wire.

Example: Next, the present invention will be explained with reference to examples.

In the drawings, reference numeral 1 denotes a ceramic substrate, which for example consists of an A1°O3- or ZrO2-ceramic or a glass-insulated (enamel-coated) metal substrate.

On this metal substrate, for example, AgPd, Pt or A
There is an electrically conductive strip 2 from u, which is connected to the electrical conductor 4 both pneumatically and mechanically, such as by sponging of the baked thick film paste 3.

The thick film paste 3 is made by, for example, DuPont.
It is available on the market under the trademark Nobui-1 (DP) 9473, and it is further described in numerous publications, for example German Patent Application No. 3 02112 or 314
It is described in No. 5583. DuPont Pace) D
AgPd-thick film pastes such as P-947,3 are baked at temperatures of about 850°C to 900°C and P-
Baking of t-Au-thick film paste also depends on temperature. 1600
The highest baking temperatures of up to 500°C are used for pure platinum-thick film pastes, and the lower baking temperatures of about 500°C are
Required for Ag-thick film pastes with low melting point glass frits.

The application of the thick film paste onto the electrically conductive strip 2 can be carried out in conventional manner, for example by means of a metering device, screen printing, stamping, brushing or knife application.

The contacts obtained by the method of the invention are heat resistant to values approximately comparable to the baking temperatures of the thick film pastes used. Therefore, depending on the case of use, a suitable thick-film paste can be selected without difficulty, other criteria such as electrical conductivity, processability, etc. being taken into account in the individual case.

The method according to the invention is particularly suitable for ensuring the electrical and mechanical connection of connecting lines on an electrically conductive strip, which conductive strip is coated with a ceramic substrate in the form of a membrane on its side. It is provided on top and is already firmly bonded to the substrate 1 by a sintering process before the electrical conductor is applied. Furthermore, the introduction of the thick film paste 3 for fixing the electrical conductor 4 is carried out in a separate step, independent of the provision of the electrically conductive strip #:2. Baking is also possible at the same time. Depending on its arrangement, the conductor 4 can be embedded as a wire or sheet into the thick film burst 3 previously provided on the conductive strip 2 or it can be placed on this thick film paste. can. What is essential in this case is that the electrical conductor 4 is provided on or in the thick film paste 3 before this thick film paste has dried and that a firm adhesion is therefore only obtained by the baking process. . The minimum temperature during the baking process is approximately 500℃.
Yes, it depends on the glass frit used.

Suitable electrical conductors 4 are, in particular, contact wires or sheets made of nickel, copper, silver, gold or platinum. The tight bond between the electrically conductive strip 2, the thick film paste 3 and the electrical conductor 4 is obtained by a baking process which produces high adhesive strength with low material and process-technical outlays. The strength and heat resistance are guaranteed according to the selected base).

[Brief explanation of drawings]

The accompanying drawing is a schematic representation of one embodiment of the contact obtained according to the invention. 2... Conductive strip or conductive layer, 3... Thick film 4-
St, 4... conductor

Claims (1)

[Claims] 1. In a method of bringing a conductor such as a wire, a metal sheet, etc. into heat-resistant contact with a conductive strip or a conductive layer (2), First, an electrically conductive thick film paste (3) is applied, and a conductor (4) is subsequently placed or embedded in wet state on or in this electrically conductive thick film paste, followed by > A method for bringing a conductor into heat-resistant contact with a conductive strip or layer, characterized by baking at about 500°C. 2. A method according to claim 1, wherein the baking step is carried out in a temperature range of about 500 DEG C. to 1600 DEG C., depending on the type of thick film paste (3) used. 3. Conductive layer (2) with conductor (4) already sintered first
2. The method according to claim 1, wherein the electrically conductive layer is mechanically and electrically fixed by means of a thick-film paste (3) which is baked separately after placing the electrical conductor (4) on the electrically conductive layer, in particular made of platinum. .